Endothelin Receptor-A Inhibition Decreases Ductular Reaction, Liver Fibrosis, and Angiogenesis in a Model of Cholangitis.

BACKGROUND & AIMS: Primary sclerosing cholangitis (PSC) leads to ductular reaction and fibrosis and is complicated by vascular dysfunction. Cholangiocyte and endothelial cell crosstalk modulates their proliferation in cholestatic models. Endothelin (ET)-1 and ET-2 bind to their receptor, ET-A, and cholangiocytes are a key source of ET-1 after bile duct ligation. We aimed to evaluate the therapeutic potential of ET-A inhibition in PSC and biliary-endothelial crosstalk mediated by this pathway. METHODS: Wild-type and multidrug resistance 2 knockout (Mdr2-/-) mice at 12 weeks of age were treated with vehicle or Ambrisentan (ET-A antagonist) for 1 week by daily intraperitoneal injections. Human control and PSC samples were used. RESULTS: Mdr2-/- mice at 4, 8, and 12 weeks displayed angiogenesis that peaked at 12 weeks. Mdr2-/- mice at 12 weeks had enhanced biliary ET-1/ET-2/ET-A expression and secretion, whereas human PSC had enhanced ET-1/ET-A expression and secretion. Ambrisentan reduced biliary damage, immune cell infiltration, and fibrosis in Mdr2-/- mice. Mdr2-/- mice had squamous cholangiocytes with blunted microvilli and dilated arterioles lacking cilia; however, Ambrisentan reversed these alterations. Ambrisentan decreased cholangiocyte expression of pro-angiogenic factors, specifically midkine, through the regulation of cFOS. In vitro, ET-1/ET-A caused cholangiocyte senescence, endothelial cell angiogenesis, and macrophage inflammation. In vitro, human PSC cholangiocyte supernatants increased endothelial cell migration, which was blocked with Ambrisentan treatment. CONCLUSIONS: ET-A inhibition reduced biliary and liver damage in Mdr2-/- mice. ET-A promotes biliary angiocrine signaling that may, in turn, enhance angiogenesis. Targeting ET-A may prove therapeutic for PSC, specifically patients displaying vascular dysfunction.

Actualización en hipertensión arterial pulmonar / Update in pulmonary arterial hypertension

La hipertensión arterial pulmonar es una enfermedad rara y progresiva que afecta principalmente a las arteriolas pulmonares (precapilar), independientemente de la etiología desencadenante. En España se estima que la prevalencia de hipertensión pulmonar y de hipertensión arterial pulmonar es de 19,2 y 16 casos por millón de habitantes, respectivamente. El diagnóstico de hipertensión arterial pulmonar se basa en criterios hemodinámicos (presión media de la arteria pulmonar ≥ 25mmHg, presión de enclavamiento capilar pulmonar ≤ 15mmHg, y resistencia vascular pulmonar>3 unidades Wood) y por tanto requiere la realización de un cateterismo cardiaco derecho. En la práctica clínica se ha utilizado la terapia secuencial con un solo fármaco. Sin embargo, las recientes guías europeas recomiendan la terapia combinada de inicio en algunas situaciones. En esta revisión se realiza una actualización crítica de los conocimientos sobre esta enfermedad de acuerdo a las últimas guías y recomendaciones (AU)

Pulmonary arterial hypertension is a rare and progressive disease that mainly affects the pulmonary arterioles (precapillary), regardless of the triggering aetiology. The prevalence of pulmonary hypertension and pulmonary arterial hypertension in Spain is estimated at 19.2 and 16 cases per million inhabitants, respectively. The diagnosis of pulmonary arterial hypertension is based on haemodynamic criteria (mean pulmonary artery pressure ≥25mmHg, pulmonary capillary wedge pressure ≤15mmHg and pulmonary vascular resistance >3 Wood units) and therefore requires the implementation of right cardiac catheterisation. Sequential therapy with a single drug has been used in clinical practice. However, recent European guidelines recommend combined initial therapy in some situations. This review conducts a critical update of our knowledge of this disease according to the latest guidelines and recommendations (AU)

Respuesta a «Efectos del bosentán sobre la función vascular e inflamación de pacientes diabéticos con enfermedad vascular periférica» / Reply to: Bosentan effects on vascular function and inflammation in diabetic patients withperipheral vascular disease

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Sitaxsentan-induced acute severe hepatitis treated with glucocorticoid therapy.

Endothelin receptor antagonists are commonly used in the treatment of pulmonary hypertension. Sitaxsentan, a selective endothelin A receptor blocker, induces a mild transaminitis in approximately 3% to 5% of patients, but rarely an acute severe hepatitis. A case involving a 61-year-old female with sitaxsentan-induced acute severe liver failure is presented. Depite withdrawal of therapy, her liver tests failed to improve. After six weeks of monitoring, the patient was administered high-dose corticosteroids, with a good clinical and biochemical response. While endothelin receptor antagonists are postulated to cause hepatitis by inhibition of a bile salt transporter pump, an immune-mediated or idiosyncratic mechanism should be considered.

Hipertensión pulmonar tromboembólica crónica debida a trombosis venosa profunda de miembro superior por síndrome del desfiladero torácico / Chronic Thromboembolic Pulmonary Hypertension Due to Upper-Extremity Deep Vein Thrombosis Caused by Thoracic Outlet Syndrome

Se presenta el caso de una mujer de 20 años diagnosticada de tromboembolismo pulmonar (EP) y trombosis de la vena subclavia derecha atribuible a la estasis provocada por la prominencia clavicular derecha. En el seguimiento a los 10 meses la paciente desarrolló una hipertensión pulmonar tromboembólica crónica (HPTEC), instaurándose tratamiento con un antagonista dual del receptor de endotelina. Se han descrito muy pocos casos de trombosis venosa profunda de miembro superior debidos a alteraciones anatómicas. Lo excepcional del caso es que, además, la paciente desarrolló una hipertensión pulmonar postembólica crónica, cuya incidencia se estima del 0,5% del total de los EP sintomáticos(AU)

We report on a 20 year-old woman diagnosed with pulmonary embolism (PE) and right subclavian vein thrombosis attributable to stasis caused by right clavicular prominence. At the 10-months follow-up, the patient had developed chronic thromboembolic pulmonary hypertension (CTEPH), and treatment was begun with a dual endothelin receptor antagonist. Very few cases of deep venous thrombosis of upper limb have been reported in relation to anatomical abnormalities. This case is also exceptional because the patient developed a chronic thromboembolic pulmonary hypertension, whose incidence is estimated at 0.5% of all symptomatic PE(AU)

Tratamiento específico de la hipertensión arterial pulmonar. Experiencia de la policlínica de hipertensión pulmonardel Hospital Maciel, período 2009-2011 / Specific treatment of pulmonary arterial hypertension. Experience of the pulmonary hypertension clinic at the polyclinic Hospital Maciel, period 2009-2011

Introducción:la hipertensión pulmonar (HP) es una condición hemodinámica definida por un aumento de la presiónarterial pulmonar media (PmAP) 25 mmHg en reposo estimada mediante el cateterismo cardíaco derecho (CCD). Secomunica la experiencia adquirida en el diagnóstico, seguimiento y tratamiento de la hipertensión arterial pulmonar(HAP) y de la HP tromboembólica crónica (HPTEC) de la policlínica de HP del Hospital Maciel. Métodos: se analiza una cohorte de 15 pacientes (2009-2011). Se estimaron la clase funcional (CF), la prueba de caminata de 6 minutos (P6M), la excursión sistólica del plano del anillo tricuspídeo (ESPAT) y la velocidad sistólica pico(Sm). La severidad hemodinámica fue estimada por CCD. Se definió respuesta vasorreactiva aguda (RVA) positiva porel descenso de la PmAP 10 mmHg, alcanzando un valor absoluto 40 mmHg sin cambios o aumento del índice cardíaco (IC). Los datos se expresaron como media ± DS. Se empleó el test de t student pareado para comparar el efecto deltratamiento específico y el test de Kruskal-Wallis para comparaciones entre los grupos, con una p<0,05.Resultados:la edad promedio fue de 43 ± 12 años, 12 (80%) mujeres. Diez (67%) del grupo 1 y 5 (33%) del grupo 4. El20% se presentó en CF I-II y 80% en CF III-IV. El tiempo de seguimiento fue de 19 ± 11 meses. La ESPAT y la Sm basales fueron de 17 ± 7 mm y 11 ± 2 cm/s, respectivamente. La PmAP fue de 54 ± 15 mmHg, la presión auricular derecha 11± 6 mmHg, IC 2,1 ± 0,7 l/min/m2, resistencia vascular pulmonar 1.087 ± 625 dinas.s.cm-5, capacitancia pulmonar 1,3 ±0,6 ml/mmHg. Un paciente presentó RVA positiva. Se empleó sildenafil (100%), bosentan (50%) e iloprost (43%); en71% el tratamiento fue combinado. No se registró hepatotoxicidad por bosentan durante el período de seguimiento. Unpaciente murió por rechazo a recibir tratamiento específico. Los 14 pacientes restantes presentaron una mejoría de laCF (3,0 ± 0,8 versus 2,1 ± 0,8, p<0,05), así como de la P6M ...

[Pulmonary arterial hypertension in childhood]. / Pulmonale arteriële hypertensie bij kinderen in Nederland.

Progressive pulmonary arterial hypertension (PAH) is a rare condition with high morbidity and mortality. Paediatric PAH distinguishes itself from PAH in adults, but is still poorly characterized. Paediatric PAH presents itself with non-specific symptoms which often results in later diagnosis. Determination of the correct underlying diagnosis in paediatric PAH is complex, and must therefore take place at specialized centres. Paediatric progressive PAH is usually either idiopathic or associated with congenital heart disease. Pediatric PAH frequently co-occurs with dysmorphic abnormalities, which may point towards aetiological mechanisms. Recent reports suggest an improved survival and exercise tolerance due to treatment with new second-generation drugs for paediatric PAH. In the Netherlands, the care for children with PAH is centralised to guarantee the optimization of diagnosis and treatment in accordance with the most recent scientific insights.

Benefícios e limitações do tratamento atual da hipertensao arterial pulmonar / Benefits and limitations about today's treatment of pulmonary arterial hypertension

Hipertensão arterial pulmonar (HAP) é uma doença rara causada pela proliferação vascular e remodelamento, resultando no aumento progressivo da resistência vascular pulmonar e disfunção ventricular direita. Apesar de recentes avanços terapêuticos, essa doença é ainda grave e rapidamente progressiva. Existem, atualmente, três classes principais de drogas que podem ser utilizadas para o tratamento da HAP: prostanoides, antagonistas dos receptores de endotelina e inibidores da fosfodiesterase-5. Nessa revisão, discutiremos o tratamento de suporte nessa população de doentes, assim como as drogas específicas atualmente disponíveis.

Outcome of pediatric patients with pulmonary arterial hypertension in the era of new medical therapies.

Little is known about the effects of "second-generation drugs" (prostanoids, endothelin receptor antagonists, 5-phosphodiesterase inhibitors) in children with pulmonary arterial hypertension (PAH). This study describes the outcome of a national cohort of children with PAH in an era when these drugs became available. From 1993 to 2008, 52 consecutive children with idiopathic PAH (n = 29) or systemic-to-pulmonary shunt-associated PAH (n = 23) underwent baseline and follow-up assessments. Treatment was initiated depending on functional class, acute pulmonary vasoreactivity response, and drug availability. Observed survival was evaluated depending on time of diagnosis in relation to second-generation drug availability and subsequently compared to calculated predicted survival. Children for whom second-generation drugs were available had improved survival compared to their predicted survival (1-, 3-, and 5-year survival rates 93%, 83%, and 66% vs 79%, 61%, and 50%, respectively). However, this improved survival was observed only in patients for whom second-generation drugs became available during their disease course. No improved survival was observed in patients for whom drugs were available already at diagnosis. Baseline variables associated with decreased survival included higher functional class, higher pulmonary-to-systemic arterial pressure ratio, lower cardiac index, and higher serum levels of N-terminal pro-brain natriuretic peptide and uric acid. After start of second-generation drugs, functional class, 6-minute walking distance, and N-terminal pro-brain natriuretic peptide improved but gradually decreased after longer follow-up. In conclusion, survival of pediatric PAH seemed improved since the introduction of second-generation drugs only in selected patients for whom these drugs became available during their disease course. Start of second-generation drugs initially induced clinical improvements, but these effects decreased after longer follow-up.

Effect of bosentan on skin fibrosis in patients with systemic sclerosis: a prospective, open-label, non-comparative trial.

OBJECTIVES: To assess the effect of the ET-receptor antagonist bosentan on skin fibrosis and functionality in patients with SSc. METHODS: In this prospective, open-label, non-comparative trial, a total of 10 patients with SSc received 62.5 mg of bosentan twice daily for 4 weeks and then 125 mg twice daily for 20 weeks. The primary endpoint was skin thickening as measured by the modified Rodnan skin score (mRSS). Further assessments included 20 MHz ultrasound, examination of digital ulcers (DUs) and evaluation of hand function by examining patients' fist closure. Furthermore, patients with SSc used the UK SSc Functional Score (UKFS), the modified scleroderma HAQ (SHAQ) and its visual analogue scale (VAS) to rate their disability related to specific organ systems. RESULTS: The mean change from baseline mRSS (the primary endpoint) was 6.4 at Week 24 of bosentan treatment, which was statistically significant (P < 0.001). Patients with both diffuse and limited SSc exhibited a statistically significant mean difference in the mRSS. Moreover, there was a significant healing of DUs noted between baseline and at Week 24 of bosentan treatment (P < 0.001); however, the 20 MHz ultrasound and the fist closure evaluation revealed no significant differences. There were also no statistically significant changes between baseline and Week 24 in the UKFS, the modified SHAQ and its VAS. CONCLUSION: In addition to the well-known effect of bosentan in prevention of DUs, the results of this study demonstrate that bosentan may also be effective at reducing skin fibrosis in patients with SSc.

Pulmonary veno-occlusive disease: diagnostic and therapeutic alternatives.

Pulmonary veno-occlusive disease (PVOD) is a rare cause of pulmonary hypertension. Surgical biopsy was usually required for diagnostic confirmation. However, the morbidity, mortality and limited benefit of this procedure have generated discussion regarding noninvasive diagnostic techniques. We present the case of a female patient with progressive dyspnea, hypoxemia and pulmonary hypertension, the last diagnosed via catheterization. Computed tomography revealed septal thickening and diffuse micronodules. Bronchoalveolar lavage revealed occult alveolar hemorrhage. Treatment with an endothelin antagonist was started, resulting in symptomatic and functional improvement. Occult alveolar hemorrhage differentiates PVOD from idiopathic pulmonary hypertension. We believe that this finding, in combination with characteristic tomographic findings, is sufficient to establish a diagnosis of PVOD.

HIV-related pulmonary arterial hypertension: clinical presentation and management.

Pulmonary arterial hypertension (PAH) is a progressive albeit rare long-term complication of HIV infection, which has gained importance following the improved survival of HIV-infected patients with the use of HAART. The clinical and pathological findings in PAH associated with HIV infection (HIV-PAH) share many features with the idiopathic form of the disease. HIV-PAH is associated with a particularly poor prognosis and decreased survival compared with HIV-infected patients without this complication, and patients with HIV-PAH tend to die from the effects of PAH rather than as a result of their HIV infection. Prompt diagnosis and effective treatment of PAH in HIV-infected patients is therefore essential. There are currently only limited data regarding the efficacy of PAH therapies in HIV-PAH. Treatment with epoprostenol has been reported to provide benefit in some cases, but is associated with a range of problems linked to the need for continuous intravenous infusion. The dual endothelin receptor antagonist bosentan has proved to be effective in HIV-PAH without affecting the control of HIV infection, and has the benefit of oral administration. Other PAH therapies including prostacyclin analogs, phosphodiesterase type 5 inhibitors and selective endothelin receptor antagonists have yet to be trialed in this setting. Taking into account currently available data and clinical experience, a treatment algorithm for HIV-PAH based on that defined in treatment guidelines for other forms of PAH is suggested.

Doença veno-oclusiva pulmonar: alternativas diagnósticas e terapêuticas / Pulmonary veno-occlusive disease: diagnostic and therapeutic alternatives

A doença veno-oclusiva pulmonar (DVOP) é uma causa rara de hipertensão pulmonar. A biópsia cirúrgica era usualmente necessária para seu diagnóstico; entretanto, sua morbidade, mortalidade e seu impacto limitado levantou a discussão sobre o diagnóstico não-invasivo. Apresentamos um caso de uma paciente com dispnéia progressiva, hipoxemia e hipertensão pulmonar no cateterismo. A tomografia computadorizada revelou espessamento septal e micronódulos difusos. O lavado broncoalveolar revelou hemorragia alveolar oculta. Iniciou-se tratamento com antagonista da endotelina, que resultou em melhora clínica e funcional. A hemorragia alveolar oculta é uma característica da DVOP capaz de diferenciá-la da hipertensão pulmonar idiopática. Acreditamos que sua presença, associada à tomografia característica, seja suficiente para o diagnóstico de DVOP.

Pulmonary veno-occlusive disease (PVOD) is a rare cause of pulmonary hypertension. Surgical biopsy was usually required for diagnostic confirmation. However, the morbidity, mortality and limited benefit of this procedure have generated discussion regarding noninvasive diagnostic techniques. We present the case of a female patient with progressive dyspnea, hypoxemia and pulmonary hypertension, the last diagnosed via catheterization. Computed tomography revealed septal thickening and diffuse micronodules. Bronchoalveolar lavage revealed occult alveolar hemorrhage. Treatment with an endothelin antagonist was started, resulting in symptomatic and functional improvement. Occult alveolar hemorrhage differentiates PVOD from idiopathic pulmonary hypertension. We believe that this finding, in combination with characteristic tomographic findings, is sufficient to establish a diagnosis of PVOD.

Endothelin receptor antagonists in pulmonary arterial hypertension.

The endothelin (ET) system, especially ET-1 and the ET(A) and ET(B) receptors, has been implicated in the pathogenesis of pulmonary arterial hypertension (PAH). Together with prostanoids and phosphodiesterase 5 inhibitors, ET receptor antagonists have become mainstays in the current treatment of PAH. Three substances are currently available for the treatment of PAH. One of these substances, bosentan, blocks both ET(A) and ET(B) receptors, whereas the two other compounds, sitaxsentan and ambrisentan, are more selective blockers of the ET(A) receptor. There is ongoing debate as to whether selective or nonselective ET receptor blockade is advantageous in the setting of PAH, although there is no clear evidence that receptor selectivity is relevant with regard to the clinical effects of these drugs. For the time being, other features, such as safety profiles and the potential for pharmacokinetic interactions with other drugs used in the treatment of PAH, may be more important than selectivity or nonselectivity when selecting treatments for individual patients.

Tratamiento con sildenafilo y/o bosentán en niños y jóvenes con hipertensión arterial pulmonar idiopática y síndrome de Eisenmenger / Treatment with sildenafil, bosentan, or both in children and young people with idiopathic pulmonary arterial hypertension and Eisenmenger's Syndrome

Introducción y objetivos. La hipertensión arterial pulmonar tiene mal pronóstico en pacientes adultos y pediátricos. El conocimiento actual de los mecanismos que condicionan la hipertensión arterial pulmonar ha permitido descubrir medicamentos como los antagonistas de los receptores de la endotelina e inhibidores de la 5-fosfodiesterasa, administrables ambos por vía oral y generalmente bien tolerados. En este estudio se valora la capacidad funcional y la tolerancia al ejercicio en el tratamiento a largo plazo con sildenafilo o bosentán en pacientes con hipertensión arterial pulmonar idiopática y síndrome de Eisenmenger, y se comparan los resultados en ambos grupos de pacientes. Métodos. Siete pacientes fueron incluidos en el protocolo de estudio de la hipertensión arterial pulmonar, y en ellos se confirmó el diagnóstico de hipertensión arterial pulmonar idiopática. Se trató con sildenafilo a 5 pacientes y con bosentán a 2. Cinco pacientes con comunicación interventricular no restrictiva e hipertensión arterial pulmonar fueron tratados con sildenafilo. En uno de ellos se añadió bosentán al tratamiento con sildenafilo. Resultados. El sildenafilo y el bosentán mejoraron significativamente la capacidad de ejercicio en pacientes con hipertensión arterial pulmonar idiopática. El efecto fue menor en los pacientes con fisiología de síndrome de Eisenmenger. La mejoría en la clase funcional de la Organización Mundial de la Salud fue mayor en los pacientes con hipertensión arterial pulmonar idiopática, aunque fue significativa en ambos grupos. Conclusiones. El tratamiento a largo plazo con sildenafilo y bosentán mejora la capacidad de ejercicio y la clase funcional en la hipertensión arterial pulmonar idiopática y debida a cardiopatías congénitas. Los cambios son más llamativos en los pacientes con hipertensión arterial pulmonar idiopática (AU)

Introduction and objectives. Pulmonary arterial hypertension carries a poor prognosis in both adult and pediatric patients. Current understanding of the mechanisms underlying pulmonary arterial hypertension has enabled the rapid development of appropriate drugs, such as endothelin receptor antagonists and 5-phosphodieste-rase inhibitors, that can be administered orally and which are generally well tolerated. The aims of the present study were to evaluate functional class and exercise capacity following long-term treatment with sildenafil or bosentan in patients with idiopathic pulmonary arterial hypertension and Eisenmenger's syndrome and to compare results in the two groups. Methods. Seven patients were included in the pulmonary arterial hypertension study, and diagnoses of idiopathic pulmonary arterial hypertension were confirmed. Five patients were treated with sildenafil, while two received bosentan. The five patients with a non-restrictive ventricular septal defect and pulmonary arterial hypertension were treated with sildenafil. In one patient, bosentan was added to the sildenafil. Results. Both sildenafil and bosentan significantly improved exercise capacity in patients with idiopathic pulmonary arterial hypertension. The treatment effect was less in those with Eisenmenger physiology. Although the improvement in World Health Organization functional class was greater in patients with idiopathic pulmonary arterial hypertension, it was significant in both groups. Conclusions. Long-term treatment with sildenafil and bosentan improved both exercise capacity and functional class in patients with idiopathic pulmonary arterial hypertension and in those with hypertension due to congenital heart disease. The changes were more marked in patients with idiopathic pulmonary arterial hypertension (AU)

Treatment of pulmonary arterial hypertension.

OBJECTIVE: To perform a review of the diagnostic and therapeutic management of pulmonary hypertension in the pediatric population, with emphasis on pharmacological factors. SOURCES: Electronic search of publications on the MEDLINE/PubMed, LILACS and Cochrane Collaboration databases. The search strategy adopted gave priority to the identification of clinical trials (controlled or uncontrolled), systematic reviews and directives published during the last 10 years. SUMMARY OF THE FINDINGS: Many advances have been incorporated into our understanding of pulmonary hypertension during recent years. Issues related to differences in the pathophysiological mechanism of the disease between different age groups have altered both the treatment and prognosis of patients. The combined effect of more selective vasodilatory properties and antiproliferative action and the employment of new drugs are the basic principles of new treatment proposals. In order to be able to gauge the benefits associated with the use of these new therapies, it is of fundamental importance that all patients have their disease correctly diagnosed, the degree of functional compromise classified and their vascular reactivity capacity established, which is more difficult with pediatric patients. CONCLUSIONS: To date there is no treatment that can be considered ideal for the management of pulmonary hypertension. With reference to the possibility of employing new drugs, the majority of studies that have been published were undertaken with adult populations. Few data are available on children, and the majority of studies are uncontrolled trials or case series. Taking into account differences that have already been established between different age groups in terms of disease mechanisms and prognostic aspects, it is difficult to claim that these drugs can be incorporated into the treatment of childhood pulmonary hypertension with the same indications and results.